content/snippets/js/s/copy-array.md
---
title: How can I clone an array in JavaScript?
shortTitle: Clone an array
type: question
language: javascript
tags: [array]
cover: colorful-plastic
excerpt: Pick up a few new tricks which you can use to clone arrays in JavaScript.
listed: true
dateModified: 2021-06-12
---
JavaScript provides quite a few ways to clone an array, most of which are pretty similar in terms of performance and results. Here's a quick rundown of some of the available options.
## The spread operator
ES6 introduced the spread operator (`...`), which provides probably the easiest and most common way to create a shallow clone of an array.
```js
let x = [1, 2, 3, 4];
let y = [...x];
```
## Array.from()
`Array.from()` has a very powerful API that can be used for many different things, including creating a copy of an array.
```js
let x = [1, 2, 3, 4];
let y = Array.from(x);
```
## Array.prototype.slice()
Similarly to the spread operator, `Array.prototype.slice()` can be used to create a shallow copy of an array.
```js
let x = [1, 2, 3, 4];
let y = x.slice();
```
## Array.prototype.map()
Looking into one of the more unorthodox options, `Array.prototype.map()` can be used to map each element of an array to itself to create a new array.
```js
let x = [1, 2, 3, 4];
let y = x.map(i => i);
```
## Array.prototype.filter()
Similarly, `Array.prototype.filter()` can be used to return `true` for each and every element, resulting in a new array with all of the original array's elements.
```js
let x = [1, 2, 3, 4];
let y = x.filter(() => true);
```
## Object.assign()
Finally, `Object.assign()` can be used in the exact same way as it's used to create a clone of an object, but for an array instead.
```js
let x = [1, 2, 3, 4];
let y = Object.assign([], x);
```
## structuredClone()
If you're looking to clone an array that contains objects, functions or class instances, you can use the `structuredClone()` global function, which can be used to deep clone objects.
```js
const a = [{ foo: 'bar' }, { baz: 'qux' }];
const b = structuredClone(a); // a !== b, a[0] !== b[0]
```
> [!NOTE]
>
> The `structuredClone()` function is a fairly recent addition to the language. Even so, it's supported by all modern browsers and Node.js since **v17.0.0**.